Sacramento airport was not the only one. Check out this photo I snapped at the Burbank terminal last Friday:

There was nobody in line at the Southwest counter, or at the TSA checkpoint either. I literally walked all the way through to the x-ray machine, and took my time unloading my laptop and emptying my pockets while I made conversation with the TSA guards. Trying to sound friendly and upbeat, I said "Wow, where is everybody?" One of them replied, "It's been like this all week, and I've never seen it this way. It's a little scary."